>Microsoft's concern is recent rootkit malware that loads before Windows even boots.
Nothing recent about it; boot sector viruses have been around way longer than Windows. I remember getting one on my 386DX from a floppy I'd used to grab a shareware version of Commander Keen from our local public library. Pain in the ass to clean up.
Boot viruses were to major form of viruses back then, there was a fun one that reversed your mouse's y-axis after a while. There weren't many destructive ones though.
Nothing recent about it; boot sector viruses have been around way longer than Windows. I remember getting one on my 386DX from a floppy I'd used to grab a shareware version of Commander Keen from our local public library. Pain in the ass to clean up.